Ethanol Better Than Gasoline, If Done Right

Ethanol made in plants that also generate power from waste biomass are more efficient and generate less greenhouse-gas emissions than making petroleum-based gasoline, a new study says. Mark it as another salvo in the ongoing debate over the biofuel's environmental benefits.

But given that one of the key researchers involved in the report is Lee Lynd, a Dartmouth professor and co-founder of cellulosic ethanol startup Mascoma Corp., it's likely the report's conclusions will be taken with skepticism by ethanol detractors.

The Role of Biomass in America's Energy Future, or RBAEF, project has posted its papers online for skeptics to peruse. It examines 14 different ways of making biofuel, whether from carbohydrate feedstocks like corn or sugarcane or from non-food materials like grasses, corn stalks and other sources.

Plants that make biofuel from carbohydrates and use the leftover material to generate electricity or make cellulosic ethanol are the "most promising" of the production types studied, the researchers report.

But "mature" cellulosic ethanol production technologies can still get to production costs that will price them competitively with gasoline with oil prices as low as $30 a barrel, the report claims – and reduce greenhouse gas emissions to boot.

That greenhouse-gas claim is pretty much the opposite of what Mark Jacobson, a professor of civil and environmental energy at Stanford University, has found in his studies of cellulosic ethanol.

Jacobson has said that ethanol production can lead to a net increase in greenhouse gas emissions compared to using fossil fuels. That's because it leads to changing land-use patterns that take more carbon dioxide-hungry plants out of commission, such as clearing forests to plant ethanol feedstock crops (see Report: Wind the Best Energy; Nuclear, Coal and Ethanol the Worst).

Studies like these have led some groups to call for the federal government to change policies that support the biofuel industry with tax credits (see Corn Ethanol's Subsidy Glut).

As for whether or not cellulosic ethanol can compete on price with gasoline made with $30-a-barrel oil, that remains an open question.

Several cellulosic ethanol startups are racing to open the country's first commercial-scale plant, but several have been forced to set back their timetables, primarily because it's hard to raise money for $100 million-and-up biofuel plants in the current economic climate (see (see Verenium Plans Cellulosic Ethanol Plant in Florida).

Mascoma itself announced the startup of its first cellulosic ethanol demonstration plant last month. But the plant has come online a year later than originally planned and at less than half the initially planned production levels (see Mascoma Starts Up Cellulosic Ethanol Plant Demo).